Physical Activity and Cardiovascular Risk in Black Girls is an application for a longitudinal study to investigate the physical activity patterns, the psychosocial predictors of physical activity, and the effects of physical activity changes on blood pressure and body fatness in a cohort of African-American girls, ages 11-17. The proposed study contributes to an underdeveloped area of research. Physical activity is recommended as a nonpharmacological means to modify hypertension and obesity, two cardiovascular risk factors. African-American women have low levels of physical activity and high rates of obesity, hypertension, and mortality from coronary heart disease, diabetes, and hypertensive diseases. There is an absence of longitudinal data about the physical activity habits of African-American girls even though a decline in physical activity during adolescence has been reported in other subpopulations. Within the framework of puberty and maturation, the three specific aims of the proposed research are: 1) to describe longitudinal patterns of physical activity; 2) to assess longitudinal changes in physical activity and concomitant changes in blood pressure and body fatness; and 3) to determine psychosocial predictors of changes in physical activity. We hypothesize that there will be a monotonic decrease in physical activity and that psychosocial variables will predict changes in physical activity. The study population will be 150 sixth grade African-American girls in Fort Bend Independent School District, Missouri City, Texas. The girls will be measured for four and a half years, ages 11 or 12 at entry of the study. Anthropometry, sexual maturation, blood pressure, physical activity habits and psychosocial predictors will be measured twice a year, May and November, for a total of nine examinations. Data on dietary, smoking and drinking habits will be collected annually. Activity patterns, psychosocial predictors and other habits will be assessed by interviews and questionnaires. Sexual maturation will be assessed by menarche and the Tanner stages. Skinfold and circumference measures will determine body fatness and body fat distribution. The proposed research will investigate psychosocial, behavioral and physiological cardiovascular risk factors in a subpopulation in which the need for heart disease risk reduction has been well documented. Findings will contribute to an empirical base from which health promotion and risk reduction interventions will be developed.